Tube plug



2 Sheets-Sheet 1 m V n a June. 8 1926.

I E. F. LUNDGREN TUBE PLUG Filed Sept. 1, 1923 June 8 1926.

E. F. LUNDGRE-N TUBE PLUG l. 1923 2 Sheets-Sheet 2 Filed Sept.

' awuemtoz 7 $51 ,5; Gwen W1 6 M YZM Patented June 8, 1926.

PATENT OFFICE.

ERNEST F. LUNDGREN', OIE BROOKLYN, NEW YORK.

TUBE PLUG.

Application filed September 1, 1923. Serial No. 660,492.

This invention relates to tube plugs and pertains more particularly to adevice adapted to plug the tubes of a steam boiler. It is an object ofthis invention to provide 6 a plug of the character described which willbe simple in construction and operation and which will form an effectiveclosure 'or a leaky boiler tube.

Other objects and advantages of the in- 10 vention will appearhereinafter.

A preferred embodiment of the invention selected for purposes ofillustration is shown in the accompanying drawings, in which,

Figure 1 is an elevation of the device, the parts being shown in therelative position they would occupy when in use.

Figure 2 is an elevation showing the parts in the position in which thedevice is in- 20 serted in the tube,

Figure 3 is a sectional view, the position of the parts being the sameas in Figure 2,

Figure 4 shows the device applied to a boiler tube,

Figures 5, 6 and 7 are sections on the lines 55, 66 and 7-7 respectivelyof Figure 3.

Figure 8 is a detail perspective View showing the split sleeves whichcarry the plug segments.

Referring to the drawings, the device comprises a spindle 1 upon one endof which is mounted a head 2 which may be fastened to the spindle in anysuitable manner as by the screw thread as illustrated in the preferredembodiment shown. The head consists of an annular flange 3 and aconeshaped portion 4, the cone-shaped portion of the head forming aseating surface for the inside faces 5 of the plug segments 6.

The plug proper consists of a split cone three of the alternate segmentsof which are pivoted at 7 to lugs 8 which are struck up from arms 9which extend upwardly from a bushing 10 surrounding the spindle 1. Theother three alternate segments of the plug are pivoted at 11 to lugs 12struck up from the arms 13 which extend upwardly from a bushing 14 alsosurrounding the spindle 1. The segments 6 are biased toward the.position occupied in Figures 2 and 3 by coil spring 15 interposedbetween the lower ends of each of the segments and their respectivearms.

The bushings 10 and 14 are each mounted to slide on the spindle 1, andthe bushing 10 is arranged to slide within the bushing 14. The arms 9and 13 of the bushings 10 and 14 respectively are mounted alternatelyabout the spindle and form in effect a split cylinder surrounding thesame. A series of pins 16 project outwardly from the spindle 1 and slidein grooves 17 of the bushing 10. The'length of the grooves 17 is limitedand the ends thereof cooperate with the pin 16 to form a limit stop forthe bushing 10 and the segments 6 carried thereby.

The bushing 14 is biased toward the position shown in Figure 1 by a coilspring 18 surrounding the spindle 1 and enclosed within a cylindricaljacket 19 secured to the spindle. A latch 20 is pivoted to the jacket 19at 21 and is adapted to engage the upper edge of a lip 22 formed on thebushing 14 to hold the bushing in the position shown in Figure 3 againstthe tension of the spring. A spring 23 is provided to engage the outerend of the latch to hold the latch in position to engage the bushing.

When the parts of the device are in the position shown in Figure 1, theouter surfaces of the segments 6 of the plug form a continuouscone-shaped plug, the side faces 25 of adjacent segments contact witheach other, and the inner faces 5 are pressed against the cone surface 4of the head 2 by the force of the spring 18.

If the operator. grasps the device, holding the sleeve 19 in one handand the bushing 14. in the other, a downward pull on the bushing 14against the spring 18 willmove the parts to the position shown in Figure2, the frictional contact between the bushing 10 and the bushing 14 andbetween the faces of adjacent segments carrying the bushing 10downwardly until stopped by the pins 16. In order to provide a positivemeans for sliding the bushing 10 in case the friction is insufficient,the arms 13 of the bushing 14 may be undercut to form detents 13 whichmay engage the upper edge of the bushing 10 to draw the same downwardly.The bushing 14 may continue downwardly, how

ever, until the lip 22 is engaged by the latch 20 at which time thebushing 14 will be held in its lowermost position.

It will be observed that in this position, as illustrated in Figure 2,the diameter of the split cone is less than the diameterof the cone whenthe parts are in the position shown in Figure 1. This enables the plugto be inserted in a tube 30 from the front end 31 thereof and is ofadvantage where the rear end 32 of the tube is inaccessible.

When in use, the device thus far described may be connected with anadditional spindle 33 by a bushing 34 which may be se-- cured in fixedposition by a pair of nuts 35 and 36. On the other end of the spindle 33is loosely mounted a cone 3? to plug the end 31 of the tube 30, thiscone being held in position by a cone-shaped nut 38.

In operation, when it is desired to plug the tube 30 which has beenfound to be leaking, the parts of the plug are positioned as in Figure 2and the plug is inserted from the end 31 of the tube 30 until thesegments of the cone are projected beyond the further end of the tube.The plug is then turned to a position such that the latch 20 will bearagainst the bottom of the tube, 111 order that the weight of the plugmay spring the latch, allowing the segments to assume the positionsshown in Figure 1. The diameterof the cone in this position is greaterthan the diameter of the tube, and when drawn against the end 31 of thetube, the outer surface of the cone will cooperate with the inner sidesof the tube. This cooperative relation may be adjusted to any desireddegree of tightness by the nut 38 on the opposite end of the spindle.

It will be observed that a the nut 38 is tightened, the adjacent faces25 of the cone segments will be pressed into close relationship witheach other and also that the faces 5 of the cone segments will bepressed into close relationship with the cone face 4 of the head 2. Atthe other end of the spindle the outer face 39 of the nut will cooperatewith the inner face 40 of the cone 37 to form a tight joint. It willalso be observed that the cone shape of the plugs at either end of thetube will force the ends of the tube outwardly toward the surroundingpartitions 41, thus effectively stopping any leak which may haveoccurred between the tube and the partition.

lVhen it is desired to remove the plug from the tube, the nut 38 may beloosened, and by pulling the wire 42 attached to the lug 43 struck upfrom the bushing 14, the segments may be moved to the position of Figure2 and the plug withdrawn from the tube through the end through which itwas inserted.

It is to be understood that the invention is not limited to theembodiment shown herein for purposes of illustration, but that on thecontrary it may be variously modified and embodied within the scope ofthe subjoined claims.

I claim as my invention:

1. A tube plug comprising, a split cone comprising a plurality ofabutting segments, and means whereby said segments may be separated toreduce the diameter of the cone for insertion in a tube and may berestored to abutting position to increase the diameter thereof.

2. A tube plug comprising a split cone formed of a plurality of pivotedsegments adapted to abut one against the other in substantiallywater-tight relationship when the plug is in operative position.

3. In a tube plug, a split cone comprising a plurality of pivotedabutting segments, and means to separate adjacent segments of said coneto decrease the diameter thereof.

4. In a tube plug, a plurality of pivoted segments having adjacent facesadapted to fit together, and having outside surfaces which form a splitcone, means for separating said segments whereby said segments may pivotto reduce the diameter of the cone.

5. In a tube plug, a split cone, comprising a plurality of pivotedsegments, mean to force said segments into contact with each other, andmeans whereby said segments may be separated to reduce the diameter ofthe cone.

6. In a tube plug, a spindle, a head thereon, a split cone surroundingsaid spindle comprising a plurality of segments, a pair of bushingsslidably mounted on said spindle having a plurality of arms to whichsaid segments are pivoted, and a spring to bias said bushings towardsaid head.

7. In a tube plug, a spindle, a head thereon, a split cone surroundingsaid spindle comprising a plurality of segments, a pair of bushingsslidably mounted on said spindle having a plurality of arms to whichsaid segments are pivoted, a spring to bias said bushings toward saidhead, and a latch to hold said segments in separated position.

In a tube plug, a spindle, a head mounted thereon having a cone-shapedsurface, a split cone also mounted thereon having a. plurality ofsegments, the inside faces of said segments seating against theconeshaped surface of the head, and adjacent surfaces of said segmentsseating against each other when the plug is in operative position.

9. In a tube plug, a split cone comprising a plurality of pivotedsegments, and

means for forcing said cone into contact with the cue of a tube, wherebyadjacent segments of said cone are forced into conct with each other,and the outside edge of the tube is caused to expand.

10. A tube plug, comprising, in combination a cone formed of a pluralityof segments, separate means for carrying alternate segments of saidcone, means Whereby one of said means and the segments carried therebymay have a relative longitudinal movement With respect to the other ofsaid means and its segments, and means whereby said segments may have apivotal movement with respect to their carriers.

In testimony whereof, I have signed my name to this specification this28th day of August 1923.

ERNEST F. LUNDGREN.

